The present invention relates generally to systems and methods for failure detection in computer networks, and more particularly to a system and method for isolating Fibre Channel failures in a Storage Area Network (SAN) environment.
In attempting to bring Fibre Channel solutions to market, equipment manufacturers have struggled with the problem of fault isolation in their products. For example, the basic structure of a Storage Area Network (SAN) Fibre Channel environment consists of host adapters that reside in servers, a switch, hubs, and storage systems comprised of disk array controllers (DACs) and drive enclosures. However, the functional reliability, diagnostic capability, and compatibility of the devices that make up Fibre Channel environment is often difficult to implement as envisioned by device designers. Consequently, as the technology continues to mature and to become more sophisticated, the difficulty of isolating faulty components can be expected to increase due to the management protocols and the sundry recovery procedures adopted by the various Fibre Channel components of a SAN environment.
Currently, there exists no diagnostic tool for Fibre Channel networks that provides component failure isolation capabilities. However, there are different levels of diagnostic functions that can be extracted from the management protocol of Fibre Channel components such as hubs and switches. Thus, the interpretation of the diagnostic information that can be gleaned from these sources requires an individual skilled in the knowledge of Fibre Channel protocol. Other Fibre Channel components, such as certain DACs, might have no diagnostic capabilities, leaving it up to the user to perform manual diagnostics in order to check the functionality of the DAC.
Consequently, it is desirable to provide a method for isolating Fibre Channel failures in a SAN environment thereby allowing a user to more easily identify faulty components within the network.
Accordingly, the present invention is directed to a method for isolating SAN Fibre Channel faults in both laboratory and customer site environments, thereby reducing or eliminating uncertainty typically involved in isolating faulty components and decreasing fault isolation time. The method provides multiple levels of analysis including providing diagnostic information for a component within the SAN Fibre Channel environment, the diagnostic information being suitable for indicating a fault of the component; analyzing the diagnostic information for determining a cause of a fault indicated by the diagnostic information; and furnishing a possible cause of the fault indicated by the diagnostic information based on analysis of the provided diagnostic information.
In exemplary embodiments, the method may be implemented by a Fibre Channel fault isolator coupled to the SAN. The fault isolator is comprised of a plurality of function modules, each function module providing a diagnostic function for isolating a fault of a different type of component within the SAN. In one preferred embodiment, these function modules include a switch analysis function module for analyzing a switch of the SAN to isolate fault caused by the switch, a hub analysis function module for analyzing a hub of the SAN to isolate faults caused by the hub, an internal DAC diagnostics function module for analyzing internal functionality of a DAC of the SAN to isolate faults caused by the DAC, and an external DAC diagnostics function module for analyzing external loopback functionality of a DAC of the SAN for faults caused by the DAC. Additionally, the fault isolator may include a manual loopback diagnostics function module for providing manual isolation of faults within the SAN.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.